An analysis of the impact of explosion hazards on the level of environmental safety of disposal and destruction of ammunition. An analysis of existing technologies of land reclamation that can be used for places of disposal and destruction of ammunition, and identified opportunities and limitations of their use. For the first time, a simulation model of the safety management system for land reclamation and ammunition destruction was created. During the development of the model, it is proposed to consider the parameters of the site of disposal and destruction of ammunition, which determine the parameters of explosion risk, and environmental quality indicators, as responses to the influence of factors of operation of the site of disposal and destruction of ammunition. Safety criteria are determined using a regulatory approach in three areas: current factors, explosion risk parameters and environmental quality indicators. The integrated safety criterion is defined as the highest value of all individual safety criteria.
25 November 2022 in Technogenic and Ecological Safety
The relevance of the research and the need to develop methods that allow assessing the level of safety of the disposal and destruction of ammunition sites are shown not only at the present time, but also in the future when land reclamation measures are applied. An improved criterion for assessing the safety level of the reclamation process of the lands of the disposal and destruction of ammunition sites was developed based on the use of a regulatory approach, and significant indicators were determined, namely: the probability of an explosion, the amount of excessive pressure in the air shock wave, and the level of degradation of the lands of the disposal and destruction of ammunition sites. An improved method of assessing the safety level of the process of land reclamation of the disposal and destruction of munitions by using an improved criterion for assessing the safety level of the process has been developed. The proposed method is suitable not only for long-term evaluation, but also for operational safety management of similar objects. The main advantage of the proposed method in comparison with those used today is to take into account the entire complex of active factors of explosion risk and environmental danger, while minimizing the number of significant environmental quality indicators. Thanks to this, it becomes possible to reduce the amount of calculations required for accurate assessment by a set of regulatory criteria, and also simplifies the assessment procedure without loss of accuracy.
This study seeks to improve the utilization of compressed air towards a faster fuel jettisoning, to increase the survival rate of passengers in the event of an accident or aborted takeoffs by augmenting the already existing means of dumping fuel with no considerable increase in overall weight. The aircraft fuel dump sub-system was isolated, this process was achieved with the aid of the venturi effect. The engine compressor marks the start of the aircraft fuel dump sub-system while an exterior nozzle for displacing the fuel marks its end. This system achieved jettisoning through bled-off air from the compressor, passing through a converging-diverging nozzle (primary supersonic nozzle), thereby creating a vacuum in the mixing chamber. A jet which provides a direct connection between the fuel tank and the mixing chamber sucks fuel from the tank, where bypassed air from the compressor expels the sucked air in fine particles. After running the simulation, the mass flow rate was computed. The compressed air inlet has a mass flow rate of 58.5193(Kg/S), the kerosene inlet 1.2385(Kg/S) while the outlet has a relative value of-59.6541(Kg/S).This study seeks to improve the utilization of compressed air towards a faster fuel jettisoning, to increase the survival rate of passengers in the event of an accident or aborted takeoffs by augmenting the already existing means of dumping fuel with no considerable increase in overall weight. The aircraft fuel dump sub-system was isolated, this process was achieved with the aid of the venturi effect. The engine compressor marks the start of the aircraft fuel dump sub-system while an exterior nozzle for displacing the fuel marks its end. This system achieved jettisoning through bled-off air from the compressor, passing through a converging-diverging nozzle (primary supersonic nozzle), thereby creating a vacuum in the mixing chamber. A jet that provides a direct connection between the fuel tank and the mixing chamber sucks fuel from the tank, where bypassed air from the compressor expels the sucked air in fine particles. After running the simulation, the mass flow rate was computed. The compressed air inlet has a mass flow rate of 58.5193(Kg/s), and the kerosene inlet 1.2385(kg/s) while the outlet has a relative value of -59.6541(kg/s).
12 September 2023 in International Journal of Engineering Research in Africa
An important role a landing gear plays is that it aids in the landing and takeoff of aircraft. The landing gear must be designed in such a way that it can take these stresses in static and dynamic situations. This is to accommodate both rough and smooth landings that result from various loads acting upon it, such as drag force, vertical load, and side load. In the aviation industry, landing gear stress is a key concern, and different research in this field has previously yielded excellent results. However, the time has come to raise the bar even higher. This report will focus on the optimization of the Boeing 777's nose landing gear to better withstand rough landings. During the timeframe of this research, SOLIDWORKS was utilized to model and analyze various components of the landing gear. The results summarize that a single material should be avoided throughout the components of the landing gear. Components such as pistons with a larger stress allocation should be made of titanium alloy, while components with a lesser stress allocation should be made from aluminum alloy. An important role a landing gear plays is that it aids in the landing and takeoff of aircraft. The landing gear must be designed in such a way that it can take these stresses in static and dynamic situations. This is to accommodate both rough and smooth landings that result from various loads acting upon it, such as drag force, vertical load, and side load. In the aviation industry, landing gear stress is a key concern, and different research in this field has previously yielded excellent results. However, the time has come to raise the bar even higher. This article will focus on the improvement of the Boeing 777's nose landing gear to better withstand rough landings. During the timeframe of this research, motion study in SOLIDWORKS 2020 (Stand-alone license) was utilized to model and analyze various components of the landing gear. The results summarize that a single material should be avoided throughout the components of the landing gear. Components such as pistons with a larger stress allocation should be made of titanium alloy, while components with a lesser stress allocation should be made from aluminum alloy.
30 March 2025 in Al-Qadisiyah Journal for Engineering Sciences
Researchers and the energy industry are currently focusing their efforts on optimizing the effectiveness of vertical-axis wind turbines (VAWT) to cut down on the reliance on energy supply from fossil fuels which releases gases that are toxic to the environment. As such, several methods have been applied, including increasing the velocity and modification of both the trailing and leading edges of the aerofoil. In the present investigation, numerical studies of the flow on the wind turbine blades with a NACA0015 airfoil section equipped with and without tubercles on the trailing edge were conducted using ANSYS Fluent. A computational domain of 2000mm by 35000mm was employed with the turbulence model. This two-dimensional computational fluid dynamics (CFD) analysis was performed with Ilorin, Kwara State, Nigeria wind data that was received from the Nigeria Meteorological Agency (NIMET). The modified blade with a wavelength of 0.09m and an amplitude of 0.004m is seen to have a better thrust than the unmodified blade. It produced a thrust of 118N for a tip-speed ratio (TSR) of 4.0 compared to 109N of the unmodified blade at the same TSR and that of the modified blade (1) which attains 107N. Also, its coefficient of performance is 5% and 6% higher than that of the straight and modified blades (1) respectively,suggest that an increase in the tubercle’s wavelength and amplitude increased the maximum thrust.
The finite volume method was used to study the characteristic of contaminated aviation fuel with the aim of reducing its flammability and post-impact fire. The flammability levels between pure Jet A-1 and contaminated Jet A-1 are compared using their flashpoints and fire points before and after the introduction of Liquid Nitrogen. Upon heating different mixing ratios (4:1, 3:1, and 2:1), results are analyzed to identify the best volume ratio exhibiting the highest reduction in flammability. Analysis shows that the mixing ratio of 2:1 not only froze but increased the flashpoint of the mixture from (48 ˚C–50 ˚C) to 64 ˚C. For the mixing ratio of 3:1, there was a rise in flashpoint to about 56 ˚C and partial freezing was seen at the topmost surface. At a mixing ratio of 4:1, it was observed that the effect of liquid nitrogen on Jet A-1 was minimal leading to a slight rise in its flash point (50 ˚C). Thus, liquid Nitrogen had a substantial effect on the flammability and flash point of Jet A-1 when mixed in the ratio (2:1) with a freezing time of 30 seconds and an unfreezing time of 17.5 minutes. Hence, Liquid Nitrogen can be used for the flammability reduction of Jet A-1. Keyword : post-impact fire, flashpoint testing, CFD analysis, fire safety, contamination, FEM